Trump has set the record for worst president and worst presidential candidate, but, after watching debate highlights, I think Tim Walz would have a better shot against Trump than Kamala.  Walz is more charismatic and comes across, IMO, as more authentic.  He's a better debater, better at speaking without a teleprompter.  He's not saddled with 3.5 years of economic/immigration issues.  He doesn't have the history of significant political flip-flops and he's a "he".
For the record, I'm not voting for Trump or Harris, so I don't have a dog in this fight.